The influence of essential nutrients as well as of other environmental factors upon the normal development of the fetus is at present not fully understood, although the importance of nutrition in this respect has become clear in the last decade. Although considerably more information is available now than there was even five years ago, the specific roles of nutritional factors either in normal development of the embryo or neonate, or in the production of congenital anomalies, remains for the most part quite obscure. The proposed research aims to provide information concerning the influence of essential nutrients, especially zinc, in prenatal and neonatal development. Specific approaches involve: (1) better understanding of teratogenic aspects of zinc deficiency with special attention to preimplantation embryos, interaction with vitamin A, and development of pancreatic function; (2) elucidation of the role of zinc cell proliferation and its relationship to teratogenicity; (3) investigation into the nature and significance of zinc binding ligands in milk and their relationship to intestinal zinc transport in the neonate.